The marine Enchytraeidae (Oligochaeta, Annelida) of Rottnest Island, Western Australia

Abstract

Four new species of the marine enchytraeid genus Grania Southern, 1913, and two species, Grania ersei and Grania crassiducta, previously described from the Albany area of Western Australia, are reported from intertidal and shallow subtidal habitats around Rottnest Island. Two of the four new species, Grania longistyla and Grania alliata, as well as G. ersei and G. crassiducta, possess a structure unique to Grania, among the Enchytraeidae, a penial stylet. Grania vacivasa and Grania conjuncta, the remaining new species, have complex glandular and muscular penial bulbs. Grania ersei is, as in collections from Albany, the most common and abundant enchytraeid species in the habitats sampled, but G. crassiducta was also numerous. Three species of Marionina Michaelsen, 1889, found at Rottnest, Marionina nevisensis, Marionina appendiculata and Marionina coatesae, are all widespread in the Pacific, with the first two also having been found in the area of Albany. These three species are easily distinguished by their setal distributions: setae all absent, multiple in a bundle, and two in each bundle, respectively.